package com.hdy.web.handler;

import com.alibaba.excel.enums.CellDataTypeEnum;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.metadata.data.CellData;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.style.column.AbstractColumnWidthStyleStrategy;
import org.apache.poi.ss.usermodel.Cell;
import org.springframework.util.CollectionUtils;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class CustomCellWriteHandler extends AbstractColumnWidthStyleStrategy {

    private Map<Integer, Map<Integer, Integer>> CACHE = new HashMap<>();

    @Override
    protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<WriteCellData<?>> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
        boolean needSetWidth = isHead || !CollectionUtils.isEmpty(cellDataList);
        if (needSetWidth) {
            Map<Integer, Integer> maxColumnWidthMap = CACHE.computeIfAbsent(writeSheetHolder.getSheetNo(), k -> new HashMap<>());

            Integer columnWidth = this.dataLength(cellDataList, cell, isHead);
            if (columnWidth >= 0) {
                if (columnWidth > 255) {
                    columnWidth = 255;
                }

                Integer maxColumnWidth = maxColumnWidthMap.get(cell.getColumnIndex());
                if (maxColumnWidth == null || columnWidth > maxColumnWidth) {
                    maxColumnWidthMap.put(cell.getColumnIndex(), columnWidth);
                }
            }
        }
    }

    public void setColumnWidths(WriteSheetHolder writeSheetHolder) {
        Map<Integer, Integer> maxColumnWidthMap = CACHE.get(writeSheetHolder.getSheetNo());
        if (maxColumnWidthMap != null) {
            for (Map.Entry<Integer, Integer> entry : maxColumnWidthMap.entrySet()) {
                writeSheetHolder.getSheet().setColumnWidth(entry.getKey(), entry.getValue() * 256);
            }
        }
    }

    private Integer dataLength(List<WriteCellData<?>> cellDataList, Cell cell, Boolean isHead) {
        if (isHead) {
            return cell.getStringCellValue().getBytes().length;
        } else {
            if (CollectionUtils.isEmpty(cellDataList)) {
                return -1;
            } else {
                int maxLength = 0;
                for (WriteCellData<?> cellData : cellDataList) {
                    maxLength = Math.max(maxLength, getCellDataLength(cellData));
                }
                return maxLength;
            }
        }
    }

    private int getCellDataLength(WriteCellData<?> cellData) {
        CellDataTypeEnum type = cellData.getType();
        if (type == null) {
            return 0;
        } else {
            switch (type) {
                case STRING:
                    return cellData.getStringValue().getBytes().length;
                case BOOLEAN:
                    return cellData.getBooleanValue().toString().getBytes().length;
                case NUMBER:
                    return cellData.getNumberValue().toString().getBytes().length;
                default:
                    return 0;
            }
        }
    }
}